Field of the Invention
The present invention relates to a gas dissolving device and a gas dissolving method, and more particularly to a gas dissolving device and a gas dissolving method that can be provided to dissolve a gas in a liquid in a supersaturated state, and maintain such a supersaturated state in a stable manner.
Description of the Background Art
In recent years, soft drinks and the like obtained by filling a beverage such as water or tea with a gas such as carbon dioxide or hydrogen have been sold. Thus, with the intake of a gas filled into a liquid, the human body can ingest a gas not easily ingestible as is, thereby making it possible to more easily achieve the useful effects of individual gases.
For example, there are sold soft drinks obtained by filling a beverage such as water or tea with hydrogen gas. An object of such a soft drink is to reduce reactive oxygen species that exist in the human body by the intake of the hydrogen gas filled into the liquid.
On the other hand, reactive oxygen species are essential to sustaining life, playing an important role in the production of adenosine triphosphate (ATP) in a citric acid cycle and the like, and have been determined to also serve the role of eliminating foreign substances that have entered the human body. Additionally, reactive oxygen species that have not been used in a reaction in a living body and the like are normally broken down by enzymes that exist in cells. Nevertheless, all reactive oxygen species are not necessarily broken down by enzymes, resulting in excess reactive oxygen species that exist without being broken down. As a result, cells are damaged by the excess reactive oxygen species, causing sicknesses such as cancer and life-style related diseases, aging, and the like, requiring the elimination of excess reactive oxygen species for the purpose of health maintenance.
Hence, in recent years, hydrogen has been used as a substance that eliminates such excess reactive oxygen species. This is because hydrogen is highly safe as it is easily absorbed by the body due to its extremely low molecular weight, and changes to water upon reaction with reactive oxygen species, and the like. Further, hydrogen particularly selects and reduces only hydroxyl radicals among the many reactive oxygen species, and does not affect reactive oxygen species useful to the body.
Thus, the positive pathological effects of hydrogen, which is considered to lead to the prevention of illness and the promotion of health without any particular harm, are reported in many academic journals and the like, such as Non-Patent Documents 1 to 10, and are too numerous to mention.
As described above, the intake of hydrogen gas achieves the useful effects of the prevention of illness and the promotion of health. Further, the intake of other gases achieves the useful effects of the prevention of illness and the promotion of health specific to the gas. As a result, various means have been disclosed with the object to dissolve a gas such as hydrogen in a liquid.
For example, Patent Document 1 discloses a method of generating hydrogen water by bringing hydrogen gas or a mixed gas that includes hydrogen gas into contact with drinking water under pressure in an airtight container (A) to dissolve the hydrogen in the drinking water. The hydrogen water in the container (A) is then discharged for use. When an internal pressure of the container (A) has decreased, discharge is stopped. The airtight container (A) is subsequently filled with new drinking water, thereby increasing the internal pressure of the container (A). Hydrogen is then dissolved in the drinking water filled in the container (A) once again. Further, Patent Document 2 discloses a hydrogen water provided to a beverage, wherein hydrogen water containing microbubbles of hydrogen gas having a particle size of about 1 μm to 50 μm is obtained by passing an aqueous solution, having hydrogen gas dissolved therein to a saturated state, through small holes of an orifice to release pressure, thereby producing the dissolved hydrogen gas as fine air bubbles. These fine air bubbles are then introduced to and passed through a net member, thereby refining the air bubbles to microbubbles having a particle size of about 1 μm to 50 μm. Furthermore, Patent Document 3 discloses a hydrogen water producing device that includes a condensation device that generates condensation by condensing moisture in air, a hydrogen water generating device that generates hydrogen water having active hydrogen dissolved therein by producing a hydrogen producing reaction with this condensation, a filter unit that removes impurities from this hydrogen water to form hydrogen water, and a drinking water server that stores and supplies this hydrogen water as drinking water.
Further, Patent Document 4 discloses a device for producing water with added hydrogen that includes hydrogen in large amounts as microbubbles, the device comprising (a) a tube body, (b) a raw water supply system that is formed at one end portion of the tube body and supplies raw water at high pressure, (c) a hydrogen supply system that is connected in a water-tight manner to the tube body and supplies hydrogen substantially perpendicularly to the raw water supplied from the raw water supply system, (d) a diffusion chamber that is formed in a longitudinal direction of the tube body, downstream of the hydrogen supply system in the tube body, and diffuses a mixed fluid of raw water supplied from the raw water supply system to the tube body and hydrogen supplied from the hydrogen supply system to the tube body, (e) a porous element for causing the supplied hydrogen to pass therethrough as microbubbles, the porous element being filled into the diffusion chamber and having a predetermined hole diameter, and (f) a discharge port that is formed at the other end portion of the tube body and discharges the produced water with added hydrogen. Furthermore, Patent Document 5 discloses a continuous hydrogen water producing device comprising a water supply unit, a hydrogen supply unit, a gas-liquid mixing pump that receives supplies of water and hydrogen from each supply unit and discharges hydrogen-mixed water, an agitating unit that agitates the hydrogen-mixed water discharged from the gas-liquid mixing pump, and a gas-releasing stabilizing tank in which the hydrogen-mixed water from the agitating unit forms a predetermined retarded flow to release the hydrogen other than the dissolved hydrogen. Furthermore, Patent Document 6 discloses a hydrogen water producing device comprising a container for dissolving hydrogen in stored water, a hydrogen producing unit that produces hydrogen by hydrolysis of magnesium hydride, a hydrogen supply tube that supplies hydrogen produced in the hydrogen producing unit to the container, and a hydrogen water supply tube for supplying hydrogen water formed by dissolving pressurized hydrogen in the water stored in the container to the outside.
Further, Patent Document 7 discloses a gas dissolving device comprising a pressurized gas dissolving mechanism that dissolves gas in a liquid by bringing a pressurized liquid and a pressurized gas into contact with each other, and a pressure reducing mechanism located after the pressurized gas dissolving mechanism in a liquid flow passage. The pressure reducing mechanism causes the pressurized liquid to flow on an inner side of a plurality of capillaries, thereby reducing the pressure of the liquid.